MarqueeLabel is a functional equivalent to UILabel that adds a scrolling marquee effect when the text of the label outgrows the available width. The label scrolling direction and speed/rate can be specified as well. All standard UILabel properties (where it makes sense) are available in MarqueeLabel and it behaves just like a UILabel.
MarqueeLabel now uses ARC by default. If you want to use it in a non-ARC project you can use the non-ARC branch, however that branch probably won't see any updates in the future.
- Add MarqueeLabel.h and MarqueeLabel.m to your project.
- Add QuartzCore.framework to your project frameworks.
- Import MarqueeLabel.h and replace your UILabels with MarqueeLabels as needed.
MarqueeLabel supports moving the label at either a defined rate (points per second) or duration (seconds). The animation curve can also be defined, and defaults to UIViewAnimationOptionCurveEaseInOut. It also features a variable-length fade at the left and right side view borders, in order to fade the label text into the background rather than simply being chopped off.
Replace:
UILabel *lengthyLabel = [[UILabel alloc] initWithFrame:labelCGRectFrame];
With:
MarqueeLabel *scrollyLabel = [[MarqueeLabel alloc] initWithFrame:labelCGRectFrame duration:8.0 andFadeLength:10.0f];
This creates a MarqueeLabel that will scroll across its content in 8.0 seconds, and adds 10.0 point long fade at the left and right boundaries.
If you'd rather have a label that scrolls at a specific rate (points per second), instead of completing the scroll in a specific time frame, you can use this:
MarqueeLabel *scrollyLabel = [[MarqueeLabel alloc] initWithFrame:labelCGRectFrame rate:50.0 andFadeLength:10.0f];
Check out MarqueeLabel.h for more features, with explanations in the comments there:
- Scrolling diretion (left->right, right->left, and continuous)
- Label edge fades
- Pausing/unpausing the scrolling of the label
- Tap to scroll once
MarqueeLabel is based on UIView animations, which does cause some problems when views appear and disappear and the repeating animation is stopped by iOS and does not automatically restart. To combat this, MarqueeLabel provides a few class methods that allow easy "restarting" of all MarqueeLabels associated with a UIViewController. Specifically, the class method viewControllerDidAppear: is intended to be called when your UIViewController appears or is revealed (presenting a modal view controller pauses repeating animations!).
controllerLabelsShouldLabelize: and controllerLabelsShouldAnimate: are more for convienience, allowing labelizing and re-animating all labels of a UIViewController. Labelizing can be useful for performance, such as labelizing all MarqueeLabels when a UITableView/UIScrollView starts scrolling.
- Any ideas?
Charles Powell
Give me a shout if you're using this in your project!